Triparental ageing in a laboratory population of an insect with maternal care

Parental age at reproduction influences offspring size and survival by affecting pre- and postnatal conditions in a wide variety of species, including humans. However, most investigations into this manifestation of ageing focus upon maternal age effects; the effects of paternal age and interactions between maternal and paternal age are often neglected. Furthermore, even when maternal age effects are studied, pre- and postnatal effects are often confounded. Using a cross-fostered experimental design, we investigated the joint effects of prenatal paternal and maternal and postnatal maternal ages on five traits related to offspring outcomes in a laboratory population of a species of burying beetle, Nicrophorus vespilloides. We found a significant positive effect of the age of the egg producer on larval survival to dispersal. We found more statistical evidence for interaction effects, which acted on larval survival and egg length. Both interaction effects were negative and involved the age ...